I doubt you would notice much difference in performance between the ST and Ultra Flow on your car. I'm running the 2.5" 17749's and managed the ET's in my sig. The mufflers are at least 12 years old and although still pretty quiet are in need of replacement.
Will probably switch out to 3" straight through type mufflers and report back on performance gains if any. Thinking of going with the Magnaflow large case 5x11 22" long 12578. Suppose to be almost as quiet as the 17749 Dynomax but will be a tight fit.
Your car sounds almost exactly like mine in that clip.
__________________
68 GTO,3860#
Stock Original 400/M-20 Muncie,3.55’s
13.86 @ 100
Old combo:
462 10.75 CR,,SD 330CFM Round Port E's,Old Faithful cam,Jim Hand Continental,3.42's.
1968 Pontiac GTO : 11.114 @ 120.130 MPH
New combo:
517 MR-1,10.8 CR,SD 350CFM E's,QFT 950/Northwind,246/252 HR,9.5” 4000 stall,3.42's
636HP/654TQ
1.452 10.603 @ 125.09
http://www.dragtimes.com/Pontiac-GTO...lip-31594.html
|